Search for Jonathan Arthur Ciener firearms.

$150 for .22 units for AR's or Mini-14's. They weigh 1 lb, the caliber swap takes 20 seconds, group size of shots and POI on the target are plenty close enough for training and small game taking. No, you do not benefit from having a "dedicated" .22lr upper for the AR. I had one, sold it within a month of checking it out. lost $100 on the deal, couldn't wait to get my money out of it.